Production of light-sensitive diazotype layers



Patented May 16, 1939 PATENT OFFICE PRODUCTION or LIGHT-SENSITIVE nmzomnLAYERS Maximilian Paul Schmidt and Georg Werner,

Wiesbaden-Biebrlch, Germany,

assignors to Kalle & Co. Aktiengesellschatt, Wiesbaden- Biebrich,Germany No Drawing. Application March 27, 1937, Serial No. 133,384. lnGermany April 22, 1936 9 Claims.

The present invention relates to the production of light-sensitivediazotype layers.

Of the diam-compounds proposed for the positive diazo-type process onlythe diazo-compounds of the o-aminonaphthols and p-diamines have beenable to attain any considerable practical importance. Thesediam-compounds are very light-sensitive,possess good lasting propertiesand are more or less coloured. Moreover they fade 10 during theexposure, so that a good white ground is obtained, and, when suitableazo-components are employed, they give dark colour tones.

The employment of other previously proposed coloured and stablediazo-compounds is open in part to the objection that theirlight-sensitiveness is low or that they do not fade sufllciently, whichgives rise to prints having poor contrast. In particular, with thecompounds in question the desired dark and strong colour tones aregenerally not obtained.

It is an object of the invention to produce new diazotype layers of hightechnical value. These layers can beapplied in the usual manner on or ina suitable support. 7

It has been found that light-sensitive layers containing a diazocompound of a para-aminodiphenyl which carries in the nucleus carryingthe diazo group two alkoxy groups in 2- and 5- ..positions can beemployed exceptionally advantageously for the diazotype process. Thediazo compound of 4-amino-2,5-diethoxydiphenyl is a compound of thiskind. The designations 1- or 1-position, respectively, in thisspecification indicate the places at which the benzene nuclei of thediphenyl are combined with one another. As alkyl groups in the alkoxygroups, methyl and ethyl are of particular value. The alkyl groups mayalso be propyl or butyl groups. Alkyl resi-.

dues of higher molecular weight are less suitable. 4 The compounds namedare highly coloured, lasting and of good light-sensitiveness and theygive,

even when the ordinary azo coupling components--for example,phloroglucine-are employed, dark colour tones which are fast to light.

The. new diam-compounds generally couple rather energetically, so thatthey are particularly suitable for the wet dia'zotype process. They may,however, also be applied to a base together with azo-jcomponents whichcouple more slowly,

such as, for example, naphthol sulphonic acids.

Layers are then obtain'edwhich can be developed either by the dryprocess withammonia, or by the wet process, for example with sodasolution. In certain circumstances a paper containing thediazo-compound-if desired, together, with an Good results are inparticular obtained with 5 I such compounds as contain in addition alsoether groups in the other benzene nucleus preferably in 4-position, suchas, for example the diazo-compound of4-amino-2,5-diethoxy-4'-methoxy-diphenyl; 'As ether groups in thenucleus contain- 10 ing no diazo group methoxy-and-ethoxy groups areparticularly suitable. In place of these groups also a methyl group canbe employed. Such bodies substituted inboth nuclei give particularlydeeply coloured layers, so that when copying the 15 formation of theimage can be very readily followed. The layers may be exposed by the aidof the various customary sources of light. If desired, still furthersubstituents, such as alkyl groups or halogens, may be introduced intothe 20 molecule of the diam-compound, whereby the colour tones are moreor less altered.

Examples of some preferred methods of carrying the invention intopractice are set forth below: 25

(1) A 3% aqueous solution of the diazo-compoundof,4-a1nino-2,5-diethoxydiphenyl which for the purpose of stabilizationalso contains a suitable acid, such as tartaric acid or boric 35 acid,and, if desired, a means for preventing yellowing, is painted on to abase of the usual kind and is exposed behind a pattern. By developmentwith a weakly alkaline phloroglucine solu-- tion, for example a solutioncontaining sodium 4 acetate, prints with brownish black lines are ob-'.taine'd.

(2) 31 grammes of the hydrochloride of the diazo-compound oi 4-amino-2,5,4'-trimethoxydigrammes of tri-sodium citrate, 4 grammes ofphloroglucine and 15 grammes of acid sodium 55 tartrate in 1000 c. c. ofwater is employed. Prints with beautiful black lines are thus obtained.If

desired, other developers, which are somewhat more strongly alkaline orwhich contain other coupling components, may mo be used.

(3) 15 grammes of the zinc salt of the diazocompound of4-amino-2,5-diethoxy-4'-methyldiphenyl, 20 grammes of tartaric acid, 50grammes of sodium naphthalene trisulphonate and 20 grammes of sodium1-naphthol-4,7-disulphonate are dissolved successively in 1000 cc. ofwater and coated on paper. Aiter'exposure behind a pattern the printscan be developed with ammonia gas or by the application of a weaklyalkaline solution, which, for example, may contain sodium acetate orsodium bicarbonate.

(4) 30 grammes of the hydrochloride of the diazo-compound obtained from4'-amino-2,5-diethoxy-4'-acetylaminodiphenyl, 20 grammes of citric acid,5 grammes of boric acid, grammes of ammonium sulphate, 10 grammes ofaluminium sulphate, 10 grammes of thiourea are dissolved in 1000 cc. ofwater. Paper coated with this solution is exposed after drying beneath apattern. For the development a solution of 20 grammes of phloroglucine,20 grammes of sodium acetate and 10 grammes of sodium bicarbonate in1000 c.c. of water is employed. Prints with dark brown lines areobtained.

(5) 20 grammes of the chlorhydrate of the diazo-compound of4-amino-2,5,4'-triethoxydiphenyl, 2 grammes of sodium bisulphate, 40grammes of tartaric acid, 40 grammes of aluminium sulphate, 40 grammesof citric acid and 40 g.

of thiourea are dissolved in 1000 cc. of water in the stated succession.With this solutiona suit-' able support as for instance paper orcellulosehydrate foil is coated or impregnated respectively. The driedmaterial is developed after exposing with a solution of 20 grammes ofphloroglucine and 40 grammes of sodium bicarbonate in 1000 0.0. ofwater. Prints with black-brown lines are obtained. Instead of thementioned diazo-compound also the diazo-cor'npound of 4-amino-2,5,5-

triethoxydiphenyl or the diazo-compound of 4-amino-2,5-diethoxy-4'-methoxydiphenyl may be employed.

(6) 20 grammes of the hydrochloride of the diazo-compound obtained from4-amino2,5-di-nbutoxyi'-ethoxydiphenyl,- 40 grammes of tartaric acid, 20grammes of thiourea are dissolved in water in the stated succession.Paper is coated with this solution. The development of the material maybe efiected by means of a developer,

which contains 20 grammes of phloroglucine and 40 grammes of sodiumacetate in 1000 cc. of water.

The lines of the obtained prints are black-blue.

We claim:

1. Light-sensitive layer comprising the monovdiazo compound or a4-amino-2,5-dialkoxydiphenyl, which contains in the nucleus containingno diazo group a substituent selected from the group consisting of themethylgroup, the methoxy group and the ethoxy group.

2. Light-sensitive layer comprising the monodiazo compound of a4-amino-2,5-dialkoxydiphenyl, which contains in the nucleus containingno diazo' group in the 4-position a substituent selected from the groupconsisting of the methyl group, the methoxy group and the ethoxy group.

3. Light-sensitive layer comprising the monodiazo compound of4-amino-2,5,4-trimethoxydiphenyl.

4. Light-sensitive layer comprising the monodiazo compound of4-amino-2,5,4-triethoxydiphenyl.

-5.vLight-sensitive layer comprising the monodiazo compound of4-amino-2,5-diethoxy-4-- methoxydiphenyl. I

6. Light-sensitive layer comprising the monodiazo compound of ap-aminodiphenyl which carries in the nucleus containing-the 'diazo grouptwo alkoxy groups in 2- and 5-positions.

'7. Light-sensitive layer comprising the monodiazo compound ofap-aminodiphenyl which carries in the nucleus containing the'diazo grouptwo alkoxy groups in 2- and 5-positions wherein the said alkoxy groupscontain one to four carbon atoms.

8. Light-sensitive layer comprising the monodiazo compound of a4-amino-2,5dialkoxydiphenyl wherein the said alkoxy groups contain oneto. four carbon atoms, the diazo compound carrying. in the nucleuscontaining no diazo group a substituent selected from the groupconsisting of the methyl group, the methoxy group and the ethoxy group.

9. Light-sensitive layer comprising the monodiazo compound of a4-amino-2,5dialkcxydiphenyl wherein the said alkoxy groups contain oneto four carbon atoms, the diazo compound carrying in the nucleuscontaining no diazo group, in the 4'-position, a substituent selectedfrom the group consisting of the methyl group, the methoxy group and theethoxy group.

MAXIMILIAN PAUL SCHMIDT. GEORG WERNER.

